In recent years, there has been provided a passenger car in which a monitor for television, DVD, game, etc. is installed for rear-seat occupants. In a vehicle equipped with a 3-row seat, facing-each-other seats, or the like, a monitor is mounted on the ceiling of the vehicle. It is desirable that such a monitor is constructed in such a way that a passenger can change the direction of the screen of the monitor according to the passenger's sitting state, i.e. whether the passenger is facing forwardly or backwardly, or placed in a reclining state or the like. In other words, it is desirable that such a monitor is constructed in such away that a passenger can not only perform opening or closing of the monitor by pulling or pushing the monitor out of or in the ceiling, but also rotate (pivot) the monitor to change its direction. Furthermore, such a demand occurs not only on vehicles but also on equipment equipped with a monitor.
Patent reference 1 discloses, as a hinge device for enabling a monitor to be opened and closed and for enabling the monitor to be pivoted, “a hinge device and electronic equipment using the hinge device” which is adopted by a mobile phone and so on. The hinge device disclosed by patent reference 1 is constructed in such a way that a rotation hinge device is incorporated into a base body arranged in a connecting portion (a pivot portion) for connecting between a first member and a second member, the base body is rotatably connected to the first member by this rotation hinge device, for example, while a pivot hinge device is incorporated along a direction perpendicular to an axis of the above-mentioned rotation of the base body, and the second member is connected to the pivot hinge device. The hinge device disclosed is further constructed in such a way as to include a pivot position holding mechanism for holding a pivot position by using cam engagement for holding the rotational position in a state in which it has been rotated by a predetermined angle.
[Patent reference 1] JP,2003-120652, A
However, because the hinge device disclosed by patent reference 1 has the structure of holding the opening or closing angle of the monitor at a predetermined angle regardless of the angle of the pivot, in a case in which, for example, the angle (the visual recognition angle) at which the monitor is viewed is 120 degrees with respect to the monitor's screen and the holding mechanism is disposed at a position having an angle of 120 degrees, the monitor is held at a position (180-120 degrees) having an angle of 60 degrees with respect to the monitor's screen after the monitor has been pivoted. Therefore, because the holding mechanism works in a state in which the monitor is not open completely and is placed at an angle of 60 degrees if the viewer performs an operation of opening or closing the monitor after the monitor has been pivoted, the user feels displeasure. A further problem is that the monitor cannot be held with the above-mentioned structure when the monitor screen is positioned at an opening and closing position having an angle of 120 degrees with respect to the direction of the front of the monitor after the monitor has been pivoted.
The present invention is made in order to solve the above-mentioned problems, and it is therefore object of the present invention to provide a monitor hinge device that enables a monitor to be opened and closed and that not only enables the monitor to be pivoted and oriented toward a different direction in a state in which the monitor is open, but also can position the monitor at a predetermined position in a state in which the monitor is oriented toward the different direction.